This invention relates to a connecting device for connecting an endoscope and a television camera.
For examining the body cavity using an endoscope, there are various ways of examination such as televising the endoscopic image, photographing the image or watching the image with the eye. These ways of examination are selectively used depending upon the situation. For the endoscopic examination, it is accordingly important to be able to readily and quickly switch the various ways of examination noted above.
In order to permit endoscopic examination in a plurality of different ways, the eyepiece section of the endoscope is usually provided with a connector, which permits connection of a television camera and also examination with the eye. With this connector, however, for photographing an endoscopically examined image it is necessary to first remove the connector from the eyepiece section of the endoscope and then install a still camera on the eyepiece section. This operation cannot be done momentarily. Besides, it is liable to loose the location to be photographed while removing the connector.
To overcome these inconveniences, it has been proposed to provide the connector with another eyepiece section, on which the still camera can be installed so that it can be used both for photographing and examination with the eye.
However, when providing the connector with an eyepiece section, a prism provided as a light splitter in the connector must have such a light splitting ratio that more light is led to the side of the television camera than to the side of the eyepiece section because the light sensitivity of the usual television camera is inferior. Therefore, although there is no trouble for the examination with the eye through the eyepiece section, with the still camera mounted on the eyepiece section the light intensity that is obtainable is insufficient for the photographing. That is, reliable photographing cannot be obtained by merely providing the connector with an eyepiece section, on which the still camera can be mounted.